P R O D U C T D A T A B U L L E T I N
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E L E C T R O G A L VA N I Z E D S T E E L

ELECTROGALVANIZED
STEEL
PRODUCT FEATURES
CORROSION RESISTANCE
The zinc coating protects the base metal by providing a barrier to corrosive elements and also by the sacrificial nature of the coating.
Ultimate service life depends on coating thickness and the severity of the environment.
EXCELLENT SURFACE APPEARANCE
ZINCGRIP ELECTRASMOOTH Steel has a uniform appearance suitable for the most demanding surface critical applications.
FORMABILITY
ZINCGRIP ELECTRASMOOTH Steel can be used to produce parts containing simple bends to parts with deep drawing requirements.
PAINTABILITY
ZINCGRIP ELECTRASMOOTH Steel is readily paintable provided proper pretreatment is performed.
WELDABILITY
ZINCGRIP ELECTRASMOOTH Steel can be joined using a variety of accepted welding practices.
PROCESS
ZINCGRIP ELECTRASMOOTH Steel is produced by the GRAVITEL process.
Vertical electroplating cells are used to apply zinc to the steel substrate.
The continuous process consists of surface preparation, plating and oiling. Surface preparation is essential to assure good coating adhesion and consists of spray alkaline cleaning, brushing, electrolytic alkaline cleaning, and sulfuric acid surface activation.
In the plating section, electrical current is passed through the strip which is immersed in an aqueous solution containing zinc ions. As a result, the zinc is uniformly deposited onto the steel substrate. The thickness of the deposit is constantly monitored by an in-line x-ray coating weight gauge.
After plating, a uniform application of rust preventative oil or prelube is electrostatically deposited on the strip.
COATING CHARACTERISTICS
The electrogalvanized coating is 99.99% pure zinc and is available in a variety of coating weights. Due to the nature of the electrogalvanizing process, the zinc coating is uniformly applied throughout the coil.
A schematic of the coating cross section is shown in Figure 2.
ZINCGRIP ELECTRASMOOTH Steels can be specified in a wide range of coating weight categories as shown in Table 1. The coating designation is explained by the diagram in Figure 1. For coating weights not listed, please contact your AK Steel sales representative.
SURFACE PROTECTION AND LUBRICATION
To prevent staining in transit and storage, it is recommended that
ZINCGRIP ELECTRASMOOTH Steel be supplied with a protective oil.
Rust preventative oil is a combination of a rust preventative and a mineral oil. In some cases, a pre-applied press forming lubricant can be supplied. A dry film (acrylic/polymer) lubricant can also be supplied by further processing ZINCGRIP ELECTRASMOOTH Steel through a coil coating facility.
For other surface protection, please contact your AK Steel sales representative.
TABLE 1 – COATING WEIGHT
Coating
Designation
20G/20G
30G/30G
40G/40G
50G/50G
60G/60G
70G/70G
90G/90G
98G/98G
Coating Weight Min.
oz./ft.
2 g/m 2
0.07/0.07
20/20
0.10/0.10
0.13/0.13
0.16/0.16
30/30
40/40
50/50
0.20/0.20
0.23/0.23
0.29/0.29
0.32/0.32
60/60
70/70
90/90
98/98
Coating Weight is the single spot value on each surface of the sheet and is determined according to ASTM A879.
For one-side or differential coating, please inquire.
FIGURE 1 – COATING DESIGNATION
Min. SST* g/m 2 per side
Unexposed side
70G50GE
G = Pure Zinc
X = No Coating
Min. SST g/m 2 per side
Exposed side if applicable
E = Exposed
U = Unexposed
*SST = Single Spot Test as defined by ASTM A879.
FIGURE 2 – COATING CROSS SECTION
ZINC COATING
STEEL BASE METAL
* Layers not shown to scale.
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ELECTROGALVANIZED
STEEL
FORMABILITY AND MECHANICAL PROPERTIES
The formability of all steel products is a result of the interaction of many variables. These variables include: the mechanical properties of the steel, the forming system (tooling) used to manufacture parts, and the lubrication used during forming. Of these three, AK Steel can directly affect the mechanical properties of the steel. Tight control over chemical composition, hot rolling parameters, the amount of cold reduction, annealing time and temperature, and the amount of tempering allows the production of high quality ZINCGRIP
ELECTRASMOOTH Steels to meet customers’ requirements.
COMMERCIAL STEEL (CS)
ZINCGRIP ELECTRASMOOTH is available in a variety of base metals.
Commercial Steel (CS Type B) should be used for moderate forming or bending applications. Commercial Steel products are produced from aluminum-killed continuously cast slabs and unless otherwise specified, have a carbon content of less than 0.15%. To prevent the occurrence of fluting or stretcher strains during forming, Commercial
Steel products are temper rolled as a normal step in the mill processing.
DRAWING STEEL (DS)
For more stringent forming applications, Drawing Steel (DS Type B), should be ordered. Drawing Steel Type B has a controlled carbon content less than 0.06%C and parts formed from DS Type B steel should not exhibit stretcher strain.
EXTRA DEEP DRAWING STEEL (EDDS)
Extra Deep Drawing Steel or Extra Deep Drawing Steel Plus (EDDS+) should be ordered for the most demanding forming applications. These steels, also known as Interstitial Free (I-F) steels, are produced from vacuum degassed less than 0.010%C, titanium stabilized grades.
EDDS+ has the lowest carbon content available and has been specially formulated to be AK Steel’s most ductile product.
Typical mechanical properties are shown in Table 2, page 3.
Bake Hardenable (BH) and Dent Resistant (DR) Steels are available.
For high strength or structural applications, ZINCGRIP ELECTRASMOOTH
Steel is also available in yield strengths up to 50 ksi. (345 MPa).
PAINTABILITY
ZINCGRIP ELECTRASMOOTH Steel is particularly well suited for applications where a high quality paint finish is required.
Prior to painting, the steel should be cleaned with a mild alkaline cleaner in order to insure the removal of organic contaminants. After cleaning, a zinc phosphate or other adequate pre-treatment should be performed immediately prior to painting.
Coil coated ZINCGRIP ELECTRASMOOTH Steel is also available through
AK Steel’s arrangements with outside processors. In this case, the electrogalvanized substrate is coated in coil form with a wide range of specialty organic systems. These systems can be tailored to meet the customers’ specific needs. Coil coating options include pre-treating or pre-priming and the application of dry-film lubricants.
SPECIFICATIONS
ZINCGRIP ELECTRASMOOTH Steel is produced in conformance to the following specifications:
ASTM A1008
ASTM A568
ASTM A879
ASTM A917
SAE J1392
SAE J2340
SAE J2329
General Cold Rolled Specifications
General Requirements
Coating Weight Designation
General Requirements
HSLAS
HSLAS
Mild Steel
For any specifications not listed here, contact your AK Steel
Sales Representative.
OUTSIDE PROCESSING
Tailored blanks, tension leveling, re-squaring, slitting, cutting-tolength and coil coating are just some of the services AK Steel can provide through arrangements with outside processors.
MORE INFORMATION/TECHNICAL ASSISTANCE
AK Steel’s Technical Representatives can provide you with more detailed information concerning this product. They also are available to assist you in reviewing any welding, forming, painting, or other material selection issues.
MILL LIMITS
ZINCGRIP ELECTRASMOOTH Steel is available in thicknesses from
0.017 – 0.075 in. (0.43 – 1.90 mm), and widths up to 75 in. (1904 mm) depending on dimensions and product quality. For sizes outside these limits, please contact your AK Steel sales representative.
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ELECTROGALVANIZED
STEEL
TABLE 2 – TYPICAL MECHANICAL PROPERTIES – STANDARD GRADES
Quality Designation
Commercial Steel
(CS Type B)
Drawing Steel
(DS Type B)
Extra Deep Drawing
Steel (EDDS)
Extra Deep Drawing
Steel Plus (EDDS+)
Description
May be moderately formed.
A specimen cut in any direction can be bent flat on itself without cracking.
DS Type B may be used in drawing applications..
Interstitial Free (I-F) steels.
ksi.
29
27
24
23
YS
MPa
200
186
163
157 ksi.
45
44
42
41
UTS
MPa
310
300
292
280
Min
Elong. %
40
42
44
45 n
0.19
0.21
0.22
0.23
r m
N/A
1.7
1.8
1.8
Typical properties produced by AK Steel for these grades.
Commercial Steel, Deep Drawing Steel and Extra Deep Drawing Steel are designations of the various steels described in the ASTM specifications. Each of the steel sheet designations is associated with unique requirements for chemical composition and with non-mandatory, typical mechanical properties. All properties are tested per ASTM A370.
The following qualities are available to various customer or industrial requirements.
Bake Hardenable (BH) grades offer good formabiliy with increased strength from work hardening and subsequent paint/bake cycle.
MPa
BH 180
BH 210
BH 220
BH 240
BH 250
For strength levels not listed, please inquire.
Dent Resistant (DR) grades offer good formability with increased strength from a high work hardening rate.
MPa
DR 180
DR 190
DR 210
High Strength Low Alloy Steel (HSLAS) ksi. MPa
HSLAS 36 250
HSLAS 40 280
HSLAS 45 300
HSLAS 50 340/350
TABLE 3 – ENGINEERING PROPERTIES
Young’s Modulus of Elasticity
Density
Coefficient of Thermal Expansion
Thermal Conductivity
Specific Heat
Electrical Resistivity
200 x 10 3 MPa at 20 °C
7.87 g/cm 3 at 20 °C
Low-Carbon/HSLAS:
12.4 μm/m/°C in 20 – 100 °C range
I-F Steel:
12.9 μm/m/°C in 20 – 100 °C range
Low-Carbon/HSLAS: 89 W/m°C at 20 °C
I-F Steel: 93 W/m°C at 20 °C
481 J/kg/°C in 50 – 100 °C range
0.142 μΩ • m at 20 °C
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Headquartered in West Chester, Ohio, AK Steel is a world leader in the production of flat rolled carbon, stainless and electrical steel products, primarily for automotive, infrastructure and manufacturing, construction and electrical power generation and distribution markets. The company operates seven steel plants and two tube manufacturing plants across four states – Indiana, Kentucky, Ohio and Pennsylvania.
All of the company’s steel plants are ISO/TS 16949, ISO 9001 and ISO 14001 certified for their quality and environmental management systems. AK Steel is a publicly held company traded over the New York Stock Exchange under the symbol AKS – aligning the company with many of the most prominent corporations in America.
The information and data in this document are accurate to the best of our knowledge and belief, but are intended for general information only. Applications suggested for the materials are described only to help readers make their own evaluations and decisions, and are neither guarantees nor to be construed as express or implied warranties of suitability for these or other applications.
Data referring to material properties are the result of tests performed on specimens obtained from specific locations of the products in accordance with prescribed sampling procedures; any warranty thereof is limited to the values obtained at such locations and by such procedures. There is no warranty with respect to values of the materials at other locations.
AK and the AK Steel logo are registered trademarks of the AK Steel Corporation.
06.13.14